BI-LAYER TABLET: A CONTROLLED RELEASE DOSAGE FORM

Bi-layer tablets are developed to get immediate and sustained delivery of various drugs that have pre-defined release. In the past few decades, development in a combination of active pharmaceutical ingredients (API) in a single fixed dosage form has increased in the pharmaceutical industry, also promotes patient convenience and compliance. Bi-layer tablet plays a crucial role in the development of controlled release in order to give a successful drug delivery. Bi-layer tablets can be said to be a better option to reduce chemical incompatibilities taking place between Active Pharmaceutical Ingredients and to enable the development of various drug release profiles. Bi-layer tablet suits for sequential release of two drugs in combination or to incorporate two incompatible substances in same tablet. The bi-layer tablets are preparing by using different techniques such as OROS® push-pulls Technology, L-OROSTM Technology, EN SO TROL Techno-logy. This review article explains various techniques of bi-layer tablets and why the development and production of quality bi-layer tablets need to be carried out and basic challenges faced during the production of Bi-layer tablets. This review also describes the rationale for this combination therapy and the clinical trials that have demonstrated that these two agents can be combined without the loss of efficacy for either agent or an increase in the incidence of adverse events.